Terrorists are thought capable of launching a major biological attack on civilian populations. They might use localized biohazardous material, such as weaponized anthrax, or they might use deadly infectious agents, such as smallpox. Numerous such materials and agents exist, each with its own transmission efficiency, survivability in the atmosphere, portability, resulting symptoms, resulting morbidity and resulting mortality.
Man-made threats are not the only ones seemingly on the rise. The prospect of a pandemic from the spread of natural infectious agents also seems to be increasing. The 2003 SARS outbreak is a recent example. Putting such natural events into perspective, the 1918 influenza pandemic is widely thought to have killed more soldiers during WWI than did combat.
The inventors know of no prior biohazard protective gear designed particularly with the needs of civilians in mind. During an outbreak, public health will require widespread use of the most effective biohazard protection gear available. This entails equipment that maximizes comfort and wearability, yet minimizes the receipt and re-transmission of deadly or dangerous infectious agents. Comfort and wearability are especially important, given that users will need to wear the gear for long periods of time yet will lack the discipline which comes from military training.
Biohazard protective gear is most commonly designed for military applications. U.S. Pat. No. 6,158,429, assigned to the United States of America as represented by the Secretary of the Army, is exemplary of this art. It discloses a hood respirator for protection against biological hazards. The device disclosed therein is a complete hooded respirator assembly form fitting to the head and neck of the user. There are two HEPA filters for intake, one adjacent each cheek, as well as an exhalate “breathe-through airflow assembly.” The hooded respirator also contains a clear eye lens. The '429 patent recognizes that protection against biological agents requires only HEPA filtering, whereas protection against chemical agents, too, would require the addition of activated carbon filtering. While the '429 patent discloses filtering inhalate, it does not disclose filtration of outgoing exhalate. The device disclosed therein would therefore be of limited use during a pandemic, or in the presence of any number of infectious biological warfare agents on the battlefield or during a terrorist attack, since an infected wearer of the assembly might still be a disease vector. The '429 patent's hooded respirator also comprises a single volume enclosing the eyes, nose and mouth. This poses a fogging problem, requiring a “solution” of re-directing inhaled air across the interior of the lens. Under high humidity conditions, this anti-fogging measure might not work. Since this single volume must enclose the eyes as well as the nose and mouth, it also acts as a reservoir for CO2, reducing comfort and wearability. The hood can be hot for the wearer, too.
U.S. Pat. No. 5,957,131, also assigned to the United States of America as represented by the Secretary of the Army, discloses a biological warfare mask. The mask shown therein does not include eye protection. Instead, it shows two tubes to fit inside the nostrils, and a mouthpiece to fit inside the mouth. Thus this mask cannot protect against the many infectious agents which enter through the eyes. Nor is there filtering of exhalate.
Exemplary military gas masks, or combined chemical-biological masks, are shown in U.S. Pat. Nos. 5,181,506 and 6,176,239, respectively, both assigned to the United States of America as represented by the Secretary of the Army. These masks require carbon filtering. These masks were apparently not designed with long-term civilian use in mind. They lack any disclosure of exhalate filtering, and the '239 patent in fact attributes specific disadvantages to filtering of exhalate. And like the device of the '429 patent, the devices disclosed therein permit lens fogging through exhalate moisture build-up, which then must be abated with the “solution” of passing inhalate across the lens interior.
It is thus an object of the invention to provide a biohazard mask designed with the needs of civilian populations (adults and children) in mind.